1. Field of the Invention
The invention relates to a rotation angle sensor and a correction method for the rotation angle sensor.
2. Description of the Related Art
A rotation angle sensor using a ring magnet and a magnetic field sensor (magnetic sensor) is known (see e.g., JP-B-5434850 and JP-A-2014-219312). The rotation angle sensor is used as e.g. a steering angle sensor mounted on a vehicle to detect steering angles of a steering wheel.
The ring magnet of the rotation angle sensors is disposed around a rotating shaft, whose rotation angle is detected, so as to be integrally rotated with the rotating shaft. In general, the ring magnet used here is magnetized so as to have plural magnetic poles with different polarities arranged in a circumferential direction.
The magnetic field sensor is placed so as to face the ring magnet in a radial direction of the rotating shaft and is configured to detect magnetic field strengths in radial and tangent directions of the rotating shaft.
The rotation angle sensor is configured to determine the rotation angle of the rotating shaft based on the magnetic field strength in the radial and tangent directions detected by the magnetic field sensor.